The present invention relates to a communication apparatus for elevators, and more particularly to a communication apparatus applied to an elevator system that includes plural types of communication paths having different communication protocols from each other.
FIG. 8 shows a construction of the above type of conventional communication apparatus for elevators disclosed in Japanese Unexamined Patent Application Publication No. 10-182023, for example, and FIG. 9 shows one example of hardware configuration of a communication relay unit 23 in FIG. 8. Referring to FIG. 8, 11A-11N each denote a cage controller, GNW denotes a group network to which the cage controllers 11A-11N and a master communicating portion 23A of the communication relay unit 23 are connected, and 23 denotes the communication relay unit. HNW1-HNWk denote hall networks to which hall terminals 14-15 provided for each elevator line and slave communicating portions 23D1-23Dk of the communication relay unit 23 are connected respectively, and 26 denotes a power supply unit.
In the communication relay unit 23, 23A denotes the master communicating portion, 23B denotes a source power converter, 23C denotes a monitoring portion, 23D1-23Dk each denote a slave communicating portion, and INW denotes an internal network for connecting the slave communicating portions 23D1-23Dk to the master communicating portion 23A.
Also, in the master communicating portion 23A shown in FIG. 9, 300A and 300B denote communicating portions in parallel, 300C denotes a switching portion, 301A and 301B each denote a CPU, 302A and 302B each denote a transmitting/receiving portion, 303A and 303B each denote a ROM, 304A and 304B each denote a RAM, and 305A and 305B each denote a parallel interface portion. Further, in the slave communicating portions 23D1 and 23Dk, 307A and 307B each denote a CPU, 308A and 308B each denote a ROM, 309A and 309B each denote a DPRAM, and 310A and 310B each denote a transmitting/receiving portion.
The operation will be briefly described below. Two different networks GNW and HNW are connected to each other via the communication relay unit 23. The master communicating portion 23A of the communication relay unit 23 controls the network GNW, and the slave communicating portions 23D1-23Dk control respectively the networks HNW1-HNWk. In the communication relay unit 23, as shown in FIG. 9, the master communicating portion 23A and the slave communicating portions 23D1-23Dk transfer data between them via the dual port memories (DPRAM) 309.
However, there has been a problem that the master communicating portion 23A and the slave communicating portions 23D1-23Dk cannot read data that has been written by the CPU on the opposite side until their CPUs 301 A, 301B, 307A and 307B have finished writing of all data, and a delay in data transfer occurs.
An object of the present invention is therefore to provide a communication apparatus for elevators which can avoid a delay in data transfer for data that requires high-speed transfer.
According to a first aspect of the present invention, in a communication apparatus for elevators, a network protocol converter connected between at least two elevator communication networks, through which data is communicated with different protocols, includes a dual port memory for ordinary data transfer and a register memory for priority data transfer with interrupts at shorter intervals.
According to a second aspect of the present invention, the above communication apparatus for elevators comprises at least two elevator communication networks through which data is communicated with different protocols, and a network protocol converter connected between those networks, the network protocol converter including a dual port memory for transferring ordinary data, a register memory for transferring priority data with read/write processing at shorter intervals, and a network controller provided in each of the communication networks for selectively choosing one of the dual port memory and the register memory to perform the ordinary data transfer and the priority data transfer.
According to a third aspect of the present invention, the network controller includes a memory storing respective read/write cycles of the dual port memory and the register memory and priority data, means for setting the read/write cycles and the priority data which are stored in the memory, and network data transfer control means for, in accordance with the read/write cycles and the priority data having been set, performing the ordinary data transfer via the dual port memory and the priority data transfer for the set predetermined priority data via the register memory.
According to a fourth aspect of the present invention, the elevator communication network generates a predetermined priority transfer signal prior to data to be subjected to the priority data transfer, and the network controller includes a memory storing respective read/write cycles of the dual port memory and the register memory, means for setting the read/write cycles stored in the memory, and network data transfer control means for, in accordance with the read/write cycles having been set, performing the ordinary data transfer via the dual port memory, and when the priority transfer signal is received, performing the priority data transfer for data of a predetermined length subsequent to the priority transfer signal via the register memory.
According to a fifth aspect of the present invention, the network protocol converter includes, as the register memory for the priority data transfer, a pair of FIFO register memories capable of reading and writing data respectively only in one direction to perform data transfer in opposite directions.